Arrangement with respect to the decimal register transfer in counter devices



Jan. 27, 1970 AKE EUGEN MURVALL 3,4

ARRANGEMENT WITH RESPECT To THE DECIMAL REGISTER TRANSFER IN COUNTER DEVIC Filed Aug. 26, 1

United States Patent US. Cl. 74--409 1 Claim ABSTRACT OF THE DISCLOSURE An arrangement with respect to the decimal register transfer in counter devices of the type provided with marker wheels as coaxially journalled digit rolls or interspaced digit discs journalled in lateral array. A transfer wheel on a separate shaft is positioned between each pair of adjacent marker wheels and provided with two gear rings having the same number of teeth. One gear ring is of the Maltese cross type and meshes with a marker wheel of immediately lower order. The other gear ring meshes with a marker wheel of immediately higher order. The driving gear ring of the transfer wheel has a larger pitch diameter than the driven gear ring so that a gearing up effect is obtained between the respective marker wheel pairs in order to compensate any gear play between intermeshing gear rings.

The present invention relates to an arrangement with respect to the decimal register transfer in counter devices of the type provided. with marker wheels, as coaxially journalled digit rolls or interspaced digit discs journalled in lateral array, whereby a transfer wheel on a separate shaft is placed between each pair of adjacent marker wheels and provided with two gear rings having the same number of teeth, one gear of which being of the Maltese cross type and meshing with a marker wheel of immediately lower order and the other gear meshing with a marker wheel of immediately higher order.

During the transfer operation of the movement from one marker wheel to another by means of the transfer wheel, part of the movement is lost because of the necessary play between the gear rings in mesh, which with the usually equal diametrical pitch of the gear rings used in the prior art means that when the wheel of the single digit series rotates 36 between digits 9 and 0, the wheel of the digit series corresponding to the first digit of a two digit number rotates less than 36. Between the last mentioned wheel, which can be termed the ten series wheel, and the wheel of the digit series corresponding to the first digit of a three digit number, still more of the movement is lost, etc. The rotating movement thus will be less and less the more wheels used and this results in the digits of the different wheels not arriving in exact alignment relative to each other when the transfer movement occurs, the error in the alignment becoming greater and greater the more digit wheels that are used. Said error has a troublesome effect on the wheels, which are to be moved, or already have been moved, by the transfer wheel, in other words, when a preceding digit wheel stands on a 9 or 0 digit. This inconvenience is eliminated by the present invention, which is characterized by the driving gear ring of the transfer wheel having a larger pitch diameter than the driven gear ring so that a gearing up effect is obtained between the respective pairs of marker wheels in order to make possible a compensation of the play between intermeshing gear rings.

The invention is described more in detail in the following with reference to the accompanying drawing, in which:

3,491 ,611 Patented Jan. 27, 1970 ICC FIG. 1 shows the design used in the prior art for the transfer operation between two digit discs,

FIG. 2 shows the manner in which the transfer operation is carried out between two digit discs according to the present invention,

FIG. 3 shows in axial cross section along line III--III of FIG. 4 the transfer operation with external gearing of coaxially journalled digit rolls,

FIG. 4 shows the same arrangement as is illustrated in cross section in FIG. 3 along a plane through the centre axis,

FIG. 5 shows in cross sectional view along line V--V in FIG. 6 the transfer arrangement with internal gearing of coaxially journalled digit rolls, and

FIG. 6 shows the same arrangement as in FIG. 5 in a cross sectional along a plane through the centre of the longitudinal axis of the roll.

In the known design according to FIG. 1 it is assumed that digit disc 1 is a rotating single digit series disc carrying digits 0-9 and in its periphery being provided with a gear space 2. In adjacent arrangement to digit disc 1 transfer wheel 3 is journalled, said wheel being provided with two coaxial gear rings 4 and 5 respectively of the same diametrical pitch and in this particular case each one being provided with 4 teeth. Gear ring 4 is intended to mesh with gear space 2 of digit wheel 1 and therefore has been given the Maltese cross design, i.e. every second tooth is sliced off so that it will have about half the width or thickness of a full tooth. The other gear ring 5 meshes with a gear ring 6 of the juxtapositioned ten series digit disc 7, representing the digit series of the first digit of a two digit number, said digit disc 1 occupying the position in which it shows digit '0 having been rotated from the position wherein it showed digit 9. During the movement from 9 to 0 position digit disc 1 by means of its gear space 2 has rotated transfer wheel 3 and the latter one in its turn by means of its gear ring 5 has rotated the ten series digit wheel 7 a distance corresponding one digit. Digit disc 7 should have rotated 36 but because of the inevitable play between the gears, the movement will be less. The loss in the movement will be greater and greater the more digit discs having been used. The gear play between digit disc 1 and transfer wheel 3 is clearly seen in FIG. 1. The same unfavourable gear play occurs when digit disc 1 occupies the position in which it shows digit 9, in other words, if digit disc 1 has been rotated backwards 36. However, when digit disc 1 occupies a position outside of the 36 range, i.e. when it is an any one of the positions showing digits 1-8, transfer wheel 3 is kept in place due to two gear teeth of said wheel engaging the gearless peripheral portion of digit disc 1 and the position of transfer Wheel 3 will then not be influenced by the gear play. This manifests itself in earlier designs of the prior art where there are no problems with the digit discs not being in alignment when all the digit discs occupy positions showing digits l-8.

The object of the present invention is, irrespective of their position, to obtain the same good alignment of the digit discs as when in the prior art all digit discs were in positions showing digits 18. This object according to the invention has been obtained in a very simple and efficient manner as can be seen in FIG. 2. Transfer wheel 3 has the same number of teeth on the driven gear ring 4, as well as on the driving gear ring 5, but the pitch diameter of the driving gear ring 5 is greater than that of the driven gear ring 4. By this arrangement a gearing up of the very transfer movement is obtained. The gearing up eifect results in one of the discs falling behind in their rotating movement no matter how many digit discs are used. The smaller diametrical pitch of the driven gear ring 4 and consequently the correspondingly smaller diametrical pitch of gear space 2 of digit wheel 1 and further the higher gear ratio contribute to obtain the important advantage that all the digit discs are kept in alignment by the fact that the gearless portion of the periphery of digit wheel 1 engages two gear teeth of the gear ring 4 of transfer wheel 3 also when digit disc 1 occupies the positions showing the digit 9 or 0. In FIG. 2 it is assumed that digit disc 1 is in a position showing digit 0. The driven gear ring 4 is illustrated as having a 30% smaller pitch diameter than that of driving gear ring in which case, if the pitch diameter of digit disc 1 is 22.4 mm., the pitch diameter of gear ring 4 is 5.6 mm., the pitch diameter of gear ring 5 is 8 mm. and finally, the pitch diameter of digit wheel 7 is 20 mm., the total gear ratio will be 1.6:1.

In FIGURES 3 and 4 the same principle is illustrated as'in FIG. 2, but with one exception, viz, coaxially journalled digit drums with peripherally arranged digits being used. In order to facilitate a comparison between the two designs, the same reference numbers are given to identical parts appearing in both figures. As in the embodiment according to'FIG. 2 the size of the driven gear ring 4 in the embodiment according to FIGS. 3 and 4 is 30% smaller than that of driving gear ring 5. Thus, if the same pitch diameters are used as in FIG. 2, the gear ratio also in this case will be 1.621 between digit drum 1 and digit drum 7, and, as is evident from FIG. 3, the same good alignment is obtained for digit drum 7 as in the preceding embodiment.

In FIGS. 5 and 6 the same design principle is illustrated as in FIGS. 3 and 4 but with one exception, viz, the digit drums 1 and 7 being provided with internal 9 gears, the transfer wheel 3 being placed inside the drums.

Also in this case the driven gear ring 4 has a 30% smaller pitch diameter than the driving gear ring 5. However, the gear ratio Will not be as high as in the preceding embodiments. The difference is due to the circumstance that a reduction of the size of gear ring 4 requires a reduction of the pitch diameter of digit drum 1. The reduction of thepitch diameter of digit drum 1, however, will be percentagewise smaller than that of gear ring 4. By this arrangement a gearing up effect is still obtained between digit drum 1 and digit drum 7. If digit drum 1 has a pitch diameter of 18.2 mm., the driven gear ring 4 a pitch diameter of 4.2 mm. and the pitch diameters of driving gear ring 5 and digit drum 7 being 6 mm. and 20 mm. respectively, a gear ratio of 1.3:1 is obtained. As is evident from FIG. 3 a better alignment is obtained for digit drum 7 than in designs of the prior art having a gear ratio of 1:1.

The invention is not limited to the embodiments described above and illustrated in the drawing, but can be varied as to embodiment and details within the scope of the idea of the invention. Thus, the present invention is not limited to decimal register transfer only, but can with equally good result be applied in arrangements of the transfer of series of 12 unit numbers.

What I claim is:

1. Arrangement with respect to the decimal register transfer in counter devices of the type provided with marker wheels as coaxially journalled digit rolls or interspaced digit discs journalled in lateral array, whereby a transfer wheel on a separate shaft is placed between each pair of adjacent marker wheels and provided with two gear rings having the same number of teeth, one gear wheel of which being of the Maltese cross type and meshing with a marker wheel of immediately lower order, while the other gear wheel meshes with a marker wheel of immediately higher order, characterized by the driving gear ring of the transfer wheel having a larger pitch diameter than the driven gear ring so that a gearing up eifect is obtained between the respective marker wheel pairs in order to compensate any gear play between intermeshing gear rings.

References Cited UNITED STATES PATENTS 2,679,357 5/1954 Rosenberger 74435 X 3,107,855 10/1963 Miner 235-117 X 3,438,278 4/1969 Lehle 74-435 LEONARD H. GERIN, Primary Examiner 

